The Leopard moth, Zeuzerapyrina (L.) (Lepidoptera: Cossidae) is a serious pest of walnut and apple trees in Iran. One of the control methods for this pest is the mass trapping of males using pheromone traps. To determine the best size and color of traps, four different colors (green, yellow, white, gray) and two different sizes (delta shape with standard adhesive surface, 19 × 22 cm and trapezoidal shape with twofold adhesive surface, 36 × 22cm) were compared in a walnut orchard in Alborz province. The results showed that color did not have any significant effect on the number of males captured by traps, whereas the newly made, trapezoidal trap could capture more than twice as many as a delta trap. This means that with the same number of pheromone dispensers, more than twice as many moths could be captured by trapezoidal traps than by delta traps, which could increase the efficiency of pheromone traps in an Integrated Pest Management (IPM) program.